Winding of yarns



MalCh 30 1955 T. H. FARRAND ETAL 3,175,774

WINDING 0F YARNS Filed aan. 29, 1962 s .1%4 CSL Hi propylene.

3,l75,774 Patented Mar. 30, 1965 3,175,774 WNDING F YARNS Thomas HenryFarrand and Peter Bernard Checlrland, Harrogate, England, assignors toImperial Chemical Industries Limited, London, England, a corporation ofGreat Britain Filed Jan. 29, 1962, Ser. No. 169,554 2 Claims. (Cl.242-18) This invention relates to cone winding of extensible bulkedyarns from a substantially constant speed yarn source.

The winding on to cones of so-called bulked yarns i.e. yarns whichcontain laments which have been crimped or looped by various crimpingprocesses such as false twist crimping, stuffer b'ox crimping, deformingedge crimping or the method of crimping described in British Patent808,213 comprising passing the filaments over a narrow surface heated toa temperature above the melting -point followed by heat relaxing, isknown per se, The filaments in the yarn are made from synthetic linearpolymers such as nylon, polyethylene terephthalate and poly- Suchwinding 'of yarns on to cones is carried out by supplying the yarn froma variable speed yarn supply source, such as a freely unwinding yarnpackage.

In this known cone-winding of bulked yarns the yarn is unwound e.g. fromanother yarn package onto the cone so that variations of take-up speedand tension e.g. between nose and tail of the cone are automaticallycompensated by the varying rate of unwinding from the first package.

Difculties are experienced, however, when it is desired to wind yarnunder a controlled uniform low tension and whilst being fed to thewinding package at a constant speed, in other words when the yarn isbeing fed to the windup device by a positive feed such as a pair of niprolls.

Another diiculty which is encountered during the winding of bulked yarnsunder low tension is that packages of such low density are obtained thatthey are readily deformed by their own weight, the weight of the mandreland the mandrel arm. Increasing the tension of the yarn gives firmerpackages -but in certain circumstances the use of higher tensions leadsto reduced bulk in the yarn.

We now provide a process and apparatus for winding cones of bulked yarnwhen the yarn is supplied at constant speed, for example from a constantspeed nip roll or capstan.

The threadline becomes slack when winding at the nose of the cone andtight when winding at the base.

The detrimental effect of the threadline tension changes on the yarnproperties can be overcome by control of the distance between the yarnsource and the cone-winding mechanism.

In our invention the minimum distance between the source delivering yarnat constant speed and the conewinding mechanism is limited to an extentwhich allows the intermediate length of bulked yarn to stretch by a safeamount when winding on the base of the cone and to retain adequatetension when winding on the nose of the cone.

According to our invention we provide a process for winding extensiblebulked yarns (as hereinbefore defined) made from synthetic linearpolymer filaments, comprising unwinding the yarn from a yarn package,feeding the yarn at a constant speed if desired through a processingzone, and winding the yarn on to a cone, which is driven so that themain linear speed of the yarn being wound remains substantiallyconstant.

The factors which must be taken into account when determining theminimum distance are as follows:

(a) The amount of extension which can be applied to the yarn in theprocess without detrimental effect on its properties. This will dependupon the physical properties, particularly with respect to recovery oforiginal length when tension is relieved, in the type of yarn beingwound.

(b) The additional length of yarn which is required to make one traverseof the cone from the smaller end to the larger end of the package abovethe length which would be required to make a similar traverse on acylinder of a similar diameter to that at the small end of the package.

The additional length thus defined will be different for each coningmachine and is governed by:

(l) The mean diameter of the unladen cone.

(2) The angle of the unladen cone.

(3) The length of the traverse.

(4) The degree of linearity in the traverse.

(5) Any change of cone package angle produced by the build controlmechanism.

(6) The traverse speed relative to the rotational speed of the cone.

(7) The method employed to drive the cone.

FIGURE l illustrates a cardboard cone for winding yarn thereon.

DETERMINATION OF MINIMUM DISTANCE BE- TWEEN FEED MACHANISM AND CONEWIND- ING MECHANISM (i) The yarn is fed to the cone at a sped equal to,or slightly less than, the peripheral speed of the cone at the smallerdiameter d.

(ii) In 'one traverse from d to D on the cone, a length of yarn x iswound on the cone. The actual length of yarn being controlled by thefactor (b) (l) to (7) above.

(iii) In a similar traverse on a cylinder of diameter d a length of yarny would be wound.

(iv) The amount of additional length 'of yarn required to be deliveredin one traverse from d to D on the cone is therefore the length x-y.This is, of course, a maximum value since as the cone builds the ratioof the diameters of the build at tail and nose usually decreases.

(v) The minimum distance, s, between the yarn feed and the cone windingpoint must be adjusted to provide the length x-y and must be such thatthe value x-y is less than the distance which a length S of yarn cansafely be stretched.

Supposing that a length of yarn L can be stretched a distance l Withoutdetriment to its properties; and that when yarn is wound on Ithe noseend of the package (diameter d) it is `under sufficient tension to causeit to extend e%. The minimum distance S between the yarn feed and thecone Winder is determined by the relationsnip:

rlhe process is particularly suitable for the winding of yarns whichhave lbeen potentially crimped by a process described in British Patent808,213 and which must be thenmally treated and relaxed to bring out thefull crimp and bulk of the yarn. In any such thermal treatment ofcrimped or potentially crimped filaments it is essential that the amountof relaxation or extension taking place during the thermal treatmentshould be uniform and controlled.

Previously it has not been possible to satisfy these conditions and atthe same time wind up the yarn on cones, because of the fluctuations ofyarn wind up speed, which occur between nose and tail of the cone.

However, we have found that positive vfeed of the yarn into the thermalprocessing zone, which is desirable for Sv obtaining yarn of goodquality, may be satisfactorily combined with conventional surface-drivencone-winding machines by means of a simple device, ie. the introductionof supplementary yarn guides which extend the path ot the yarn betweenthe positive feed means and the wind-up means. Thus by making the yarnpath sufficiently long the fluctuations of tension arising `from theditlerent windup speeds at nose and tail of the cone may be made sosmall that they have no detectable effect on yarn properties. The moreextensible the yarn the shorter is the required extension of the yarnpath. One of the supplementary guides, preferably the last, may comprisemeans for increasing the yarn tension.

A suitable apparatus comprises means for unwind-ing t -e crimped orpotentially crimped yarn fro i a yarn package, a cone for winding theyarn thereon with a surface drive and reciprocating traverse means,wherein 'the yarn is unwound by positive feed means such as nipping feedrolls with means for rotating the feed means at a substantially constantspeed, suitably positioned means for extending the yarn path between thepositive feed means and the cone, such as guides so that any relaxationor extension taking place in the yarn with any liuctuations oi tensionarising from the different wind up speeds at nose and tail ot' the coneare so small that they have no detectable effect on yarn properties andmeans lfor rotating Ithe feed means and the surface drive for the coneat a predetermined adjustable speed ratio. if required, means 1 may beprovided for thermally treating the yarn between the posit-ive feedmeans and the suitably positioned for extending the yarn path.

Because of the low tensions under which the yarn or yarns are requiredto leave the positive feed means such as the nipping feed rollsdirliculties are sometimes encountered .through lapping of the yarn onthe feed rolls. To overcome this diiculty the feed rolls may be arrangedso that their axes are in a horizontal plane for feeding the yarn in avertically downward direction, if desired with means for entraining theyarn in a iluid stream and means for heating the yarn.

The preferred wind-up means comprises a mandrel carrying a cone which isdriven by a surface friction device, and a reciprocatory traversemechanism. ln order to balance the increasing load of the package as itbuilds up, a device may be attached to the mandrel comprising a camconnected to a eounterpoise arrangement which progressively lifts theload as the yarn is wound on the cone.

The attached drawings and the following example illustrate but does notlimit our invention.

FIGURE l illustrates a cardboard cone for winding yarn thereon.

FIGURE 2 is a diagrammatic front view of an apparatus for heat treatingand winding yarn on cones.

Referring to FIGURE l, this shows a cardboard cone 21 suitable forwinding yarn thereon having a package width (PW). The smaller diameternear the nose or" the cone which is to be covered with yarn is (d) andthe largest diameter of the cone to be covered with yarn is (D). Thecone side (L) extending beyond the yarn package width (PW).

FIGURE 2 is a diagrammatic drawing showing one position of amultiposition apparatus for the winding of bulked yarns onto .cones withmeans for heat relaxing the yarn during this operation.

Potentially crimped yarn on a supply package 1 1s taken over a guide 2and unwound over-end by a pair of nipping feed rolls 3 and It whichrotate at a constant reguylatable speed `and feed the yarn in avertically downward direction through a heating zone. Rotation of therolls 3 and 4 is effected by means of intermeshing gear wheels 6 one ofwhich is carried at the end of each roll and by means of a driven pinion7 which meshes with one of the gear wheels 6. EN arrow orifices 3 and 9made from low friction ceramic material are provided at the top andbottom of the zone, 4Ceramic guides 1t) and tensioning by acounterweight i5 via a cam i7 rotatable around a ioint .t9 which is thecentre of a wheel 2t), on the surface driven roll i3. The weight 1S isconnected by a flexible str-ing 24 or wire laid around wheel Zit;another ilexible string i8 or wire is connected between a non-rotatingpart of a spindle i6 bearing the cone l2 with the cam i7.

Example Potentially crimped polyethylene terephthalate filament yarn of120 denier `are wound onto ya yarn package ll as shown in the drawing.The yarn was produced by passing 'the filaments over a narrow surfaceheated to a `temperature or" 450 C. under a tension `to cause elongationin the laments of less than 10% and with a deviation in the filamentpath oi less than 5, while passing over the narrow heated surface, tothe winding device. The filaments are drawn prior to passage over `thenarrow heated surface. The filaments from the yarn package l are unwoundas illustrated in the drawing. The nipping feed rolls 3S `and t areforwarding the yarn at a speed of 1G99 it. per minute through a hotprocessing Zone maintained at a temperature of 20G C. and the yarn iswound directly onto a cone after passing over at least two :Vl-cs, iidand itl which extend the yarn path between ne nipping rolls and the cone`and the lsurface drive to 9 t'. The surface drive is rotating at asurface speed of 78S ft. per minute. A copioosly crimped bulliedpolyethylene tereplrthalate yarn is obtained and Wound ontoa cone whichis uniform and no `sloughing of the yarn occurs, although the package isquite soft and permeable to any treating fluids such as dye liquors. Theyarn has an extension of 3.5 under a tension of 22 milligrams perdenier.

"fte yarn wound on cones may, if desired, be treated with varioustreating liuids such as dye liquors or steam at superatm-osphcrictemperatures or pressures.

lt will be appreciated that `this invention enables bullied yarn to beproduced on cones more conveniently and cheaply than can be done byconventional means, since the separate operatic-n of nnwinding fromcyiinderical packages on to cones, is thereby avoided. Furthermore, theyarn may be wound on to the cones alt a very low tension.

What we claim is:

l. A process for winding extensible bullced yedn made from syntheticlinear polymer filaments selected from the group consisting ot nylon,polyethylene terephthalate and polypropylene wherein the yarn isadvanced to` a yarn winding mechanism by a yarn feeding meanscomprising: feeding the yarn at a constant speed; 'winding the yarn ontoa cone at .a substantially constant mean linea speed of the yarn 'beingwound; stretching the intermediate length of extensible Ibullied yarn.,.betere it is wound on the cone, by an amount which has no detrimentaleffect on the yarn properties when winding near the base of the cone`and to retain adequate tension when winding near the nose of the cone,said stretching be' 1g accomplished by establishing a minimum distanceof the yarn path between feeding means and the co-ne.

2. Apparatus for winding extensible bullied yarn made from .syntheticpolymer filament onto a cone comprising: constant speed positive lfeedmeans for unwinding the yarn `trom a yarn package; a cone; areciprocatory traverse mechanism for guiding .the yarn from said feedmeans onto said cone; means for rendering negligible the effect on yarnproperties of any tiuctuations of tension arising from the differentwindup speeds at the nose and the `tail of the'cone, said meansincluding drive means for rotating said cone and means establishing aminimum .nce S between said feed means and said cone 5 such that lthemean lline-nr speed fof the yarn being Wound 0n said cone remainssubstantially constant and such that the yarn stretches by a Isafeamount when Winding on the bese of the cene and retains adequate4tension when Winding en the noise of the cone, said minimum distance Sbeing determined by the relationship:

ele-e1 Where x is the yzic/tual length onf yarn wound on the cone in`one traverse from .the nose to` the hase ef the cone, y is the length`orf yarn Wound in a similar traverse on a cylinder having Ithe samediameter as the nose of the eene, (x-y) is Athe additional length of yamrequired to be delivered in one traverse on the cone, L s the length erfyan1 capable of being stretched Ia distance l,

and e is the extension `of the yarn at the nose end of the cone inpercent.

References Cited bythe Examiner UNITED STATES PATENTS DONALD W. EARKER,Primary Examiner.

JOSEPH P. STRIZAK, RUSSELL C. MADER,

15 MERVEN STEIN, Examiners.

2. APPARATUS FOR WINDING EXTENSIBLE BULKED YARN MADE FROM SYNTHETICPOLYMER FILAMENT ONTO A CONE COMPRISING: CONSTANT SPEED POSITIVE FEEDMEANS FOR UNWINDING THE YARN FROM A YARN PACKAGE; A CONE; ARECIPROCATORY TRAVERSE MECHANISM FOR GUIDING THE YARN FROM SAID FEEDMEANS ONTO SAID CONE; MEANS FOR RENDERING NEGLIGIBLE THE EFFECT ON YARNPROPERTIES OF ANY FIUCTUATIONS OF TENSION ARISING FROM THE DIFFERENTWINDUP SPEEDS AT THE NOSE AND THE TAIL OF THE CONE, SAID MEANS INCLUDINGDRIVE MEANS FOR ROTATING SAID CONE AND MEANS ESTABLISHING A MINIMUMDISTANCE S BETWEEN SAID FEED MEANS AND SAID CONE SUCH THAT THE MEANSLINEAR SPEED OF TH EYARN BEING WOUND ON SAID CONE REMAINS SUBSTANTIALLYCONSTANT AND SUCH THAT THE YARN STRETCHES BY A SAFE AMOUNT WHEN WINDINGON THE BASE OF THE CONE AND RETAINS ADEQUATE TENSION WHEN